Questions on '88-95 TBI LO5 engine convert to quasi-vortec '96-99 engine
Question:
Hello all, new to this group- Couple (or actually a barrage of questions) regarding my rebuild on my truck. I have a ‘95 extended cab GMC Z71 with the stock LO5 engine. For no real reason other than spare time this summer and excess room on my credit card, I am going to rebuild the engine. (currently has 110K mi on it, still running strong and good emissions, no leaks or burning of oil). I am, however, serious about building up the engine a little this summer (including a rebuild). Since I still get nearly 5 quarts of oil out of it every oil change, I am not planning on boring the cylinders, but I am going to put new pistons, etc in it. I do want to get the engine as close to a 96 as possible when I am done. Right now I can buy the heads (complete), intake manifold with complete fuel injection system, distributor, spark plug wires, fuel lines ,coil ,all sensors that attach to manifold, exhaust manifolds (left and right) and water pump, ecm and harness. The heads and cam are from a ‘96 engine, the ecm and harness from a 98 suburban, and the rest from an outfit that converts crate ’99s into marine engines. 1. Should this be all I need? 2. Will I need a new fuel pump? (is the one for the LO5 good enough?) 3. The computer is from a 2wd suburban (automatic) and i have a 4wd manual, will I be screwed? 4. Are there any more sensors that the Vortec has that the LO5 doesnt that I will need? 5. I am assuming that the LO5 already has a hydraulic roller cam… the rollers, lifters and pushrods should be ok to use from teh old engine? 6. would I be better getting an old tpi unit off of a pre-LT1 camaro engine and sticking with the old cam, but getting the vortec heads? and basically any other pointers you could give would be appreciated…. Thanks for at least reading all of this sh*t! -adam
Response:
- Hide quoted text — Show quoted text – > Hello all, new to this group- > Couple (or actually a barrage of questions) regarding my rebuild on my > truck. > I have a ‘95 extended cab GMC Z71 with the stock LO5 engine. For no real > reason other than spare time this summer and excess room on my credit card, > I am going to rebuild the engine. (currently has 110K mi on it, still > running strong and good emissions, no leaks or burning of oil). I am, > however, serious about building up the engine a little this summer > (including a rebuild). Since I still get nearly 5 quarts of oil out of it > every oil change, I am not planning on boring the cylinders, but I am going > to put new pistons, etc in it. I do want to get the engine as close to a 96 > as possible when I am done. Right now I can buy the heads (complete), > intake manifold with complete fuel injection system, distributor, spark plug > wires, fuel lines ,coil ,all sensors that attach to manifold, exhaust > manifolds (left and right) and water pump, ecm and harness. The heads and > cam are from a ‘96 engine, the ecm and harness from a 98 suburban, and the > rest from an outfit that converts crate ’99s into marine engines. > 1. Should this be all I need?
Since you are using a 98 VCM , you would have to make your motor OBDII compliant, which includes all the emission controls and evaporative emission controls also, otherwise the check engine light will be on all the time. You would also need the crankshaft position sensor, front timing cover and reluctor wheel but I’m not sure that the timing cover would fit on the tbi block. You would also have to install the exhaust pipes including the catalytic converter from sfi motor as this system uses 4 oxygen sensors as opposed to 2 for the tbi motor (one by each exhaust manifold, one before and one after the catalytic converter). > 2. Will I need a new fuel pump? (is the one for the LO5 good enough?)
You would have to switch fuel pumps as SFI operates at higher fuel pressures than tbi. > 3. The computer is from a 2wd suburban (automatic) and i have a 4wd manual, > will I be screwed?
You would have to reprogram the vcm to reflect the options you have. – Hide quoted text — Show quoted text -> 4. Are there any more sensors that the Vortec has that the LO5 doesnt that I > will need? > 5. I am assuming that the LO5 already has a hydraulic roller cam… the > rollers, lifters and pushrods should be ok to use from teh old engine? > 6. would I be better getting an old tpi unit off of a pre-LT1 camaro engine > and sticking with the old cam, but getting the vortec heads? > and basically any other pointers you could give would be appreciated…. > Thanks for at least reading all of this sh*t! > -adam
Response:
Thanks for the info Les… I have an option to get the computer from a ‘96… would that help any? or is it the same as the ‘98? (would like not to have to get a new Y-pipe,cats and O2 sensors).
